Automated analyzers have been developed for biochemical analysis of patient samples, such as whole blood, serum, urine, plasma and cerebral spinal fluid. Most such equipment available today is large, complicated to operate, and high in cost.
Operating such equipment is technically complicated. It typically requires specialized operators to be always available. It is usually designed for use by large laboratories serving a wide geographic area or by a large medical facility. Existing analyzers normally carry out tests in a defined sequence designed for efficient, high volume usage.
Such large scale capacity is not always required. This is particularly true in smaller medical clinic settings where large volumes of blood sample tests are not required on a daily basis.
The present chemical analyzer was developed to meet the practical needs of smaller medical settings. It is designed as a desk-top unit that can be operated without specialized laboratory training. Its capacity is adequate for meeting typical clinical applications. As an example, it can be designed to produce a maximum of 164 test results per hour for routine, single reagent chemistries. To provide a representative wide number of reagents, the analyzer has been designed to have a capacity of 40 reagent containers of two different sizes. Its capacity can be effectively doubled by using two chemistry instruments in tandem, both being controlled by a common workstation.
The compact nature of the analyzer can be partially attributed a single probe arm and pipette servicing all of the functional liquid-handling components included within it. The pipette is used for transferring both samples and reagents, as well as for diluting liquids as needed by particular test requirements.
To obtain large volumes of tests, conventional laboratory analyzers are programmed to conduct test procedures in a fixed sequence of events. While predetermined test sequences are practical in high volume chemical analyzer applications, there is a need for more flexible operation when scaling such test procedures to meet the needs of smaller medical facilities.
Most automated analyzers that accommodate samples provided in conventional draw tubes require that such tubes be delivered into the machine in carrousels or on a dedicated conveyor. The draw tubes are then processed as a group over a significant dwell time within the equipment. One feature desirable in many clinical settings is the ability to aliquot samples from a conventional draw tube without requiring the continued presence of the draw tube during the subsequent test sequences. This permits the sample material in the tube to be used simultaneously in other test procedures. For this reason, the present sample tube entry port has been designed to remove a sample promptly upon receipt of a draw tube. It then immediately releases the draw tube for any other current purposes required in the setting in which the chemical analyzer is used.
The sample tube entry port has been designed to facilitate automatic aliquoting of samples from conventional sealed draw tubes without destroying the seals closing the draw tubes. It also protects personnel from accidental contact with the sampled materials. The entry port automatically accommodates draw tubes differing from one another in both tube diameter and length.
Further details will be clear from the following description.